Seismic switch



1955 L. D. STATHAM ET AL 2,693,386 SEISMIC SWITCH Filed March 3, 1952 2Sheets-Sheet l Gum/e0 E. WH/ TE & Emu W GRANT INVENTORS.

ATTORNEY.-

louls D. STATHHM,

United States Patent "Ofifice 2,698,886 Patented Jan. 4, 1955 2,698,886.SEISMIC-SWITCH Louis D. Statham, Beverly Hills, Gilfordyls... White,

Tarzana, antlgEarl. W. ;Grant,.,Los.jAngeles, Chlif asi st th m L hu tsie i -n b An elscane, acorporationpf galifornia Application ra3,1952,;se1-t rNo. 274;s64

r n qn rel t to a echan sm th t-i mechanisms whichare actuable when themechanisms .to' become actuated whentheaccelerationv decreases to apredetermined level.

Again, we may cause the mechanism .to becomeactuated n onesense upon.acceleration of. the mechanism and operate in a difierent. sense. whenthe mechanism Idccelerates.

We have applied.this mechanismrto .a switch. as illustrated in the.drawings. The switch becomes actuated vupon deceleration but isnotactuated upon acceleration. Our invention will be further described. byreference to the draw ngs, in which Fig. 1v is a vertical sectionthrough the switch taken .on line -1.1 of ;Fig. 2;

Fig. 2 is a sectiontakenonline 2,2.of. Fi'g. 1;

Fig. 3 is a section. taken on line 3+3, of Fig.2;

Fig- 4 isa perspective view ,ofpne of. the: switch leaves;

Fig. Sis asect'ion taken on line 5 50f, Fig.3;

Big. 6 is a view similar toFig, 5. showing. theswitch on acceleration;and

Fig. 7 is a view similar to Fig. 6, showing the switch on deceleration.

The case 1 carries a cover} on whichthe pendulum plate 3 is hinged onpin 4 passing through the cover The cover 2 is suitably recessed at5.-to permit swingof';-the plate 3. On either side of the plate 3 arethe brackets 6 and 7" which counterbalance each other. They are formedwith U hooks 8 and 9 and flanges 10 and 11. The flanges are cut out at12 and 13. This forms two arms 14, one on each side of the flanges 10and 11. Spring leaf contacts 15 and 16 are positioned on one side of thecover and leaf contacts 15 and 16'. on the other side of the cover. Thisform is illustrated in Fig. 4. The spring carries a contact button onone end and is formed with a tongue 18 in the other end. They areclamped between insulating blocks 19 which are screwed into the cover 2by screws 20.

Upon the bottom of the blocks are positioned the plate 21 upon which thedog 22 is pivoted on hinge pin 23' mounted on plate 21. The dog carriesears 24 and 25, one on each side. The ears and dog form a bell cranklever arm. Springs 26 and 27 are connected to the ears 24 and and the U8. The spring acts as a bias between the spring and frame to determinethe force and therefore the acceleration necessary to actuate thependulum to rotate about the hinge. The dog is beveled at 28 and theplate 3 carries a cooperating slot 29. The plate is beveled at 30. Asuitable hole is provided at 31 in the bottom of the cover opposite thedog 22.

As shown, the plates 15 and 15 are extended under insulating fingers 31and 32 mounted on each arm 14. The springs are connected to electricalconductors 32 soldered to the lips 18 and connected to a conduitconnector.;33 mounted on the cover 2 opposite the ,dogl22.

he-i nsid .Q th spr s 26 nd 'l; iS cKed im tion. The plate 3' hangsvertically and theinsu'lated finsl .31 t s l ht y m lp at 1,5 and v. 1but e n disturb the contact 'of the contact buttons 15a andj 1 '5'b. IIowever, whenthe case is accelerated to the leftin the Y ction indicatedby the arrows in Fig. 61m Plate 3 is subjected to a force, causing it to,move' in a counterclockwise direction, i. e.,. opposite to the arrow,pro- Yldfid the acceleration is such as will generate a forcesufiicient' to overcome the spring tension. When this Qoccurs (see Fig.6) the movement v of the plate 3 lifts the fingers -31 and 32 oif thespring plates 15 ,andfl15' (see Fig. 6). The slot 29 ismoved away fromthedog 22 which thendrops away, as shown in Fig. 6, relieving thetension .of the springs 26 and 27. Thus, if the acceleration is constantor increases, the force causes 'a further movement of the plate in acounterclockwise di- -rection until the arms 14 come against the cover 2which then acts as a'stop. It is evident,however, thatinall thismovement the position of the springs is unaltered. As illustrated theswitch is in closed position.

If the case is now decelerated, the force holding the platein theposition of Fig. 6 decreases and when it reaches a value'less than thetension of the springs t he springs will force the. plate 3 to rotateclockwise (see Fig. 7). causing the fingers to descend and depress thespring'lS to open and separate the contact buttons.

To reset the switch it is merely necessary to insert a rod via hole 31and lift the dog 22 which. wills r de ,overthe bevel 3t) and enter thenotch 29.

It. is obvious that the mechanical motion of the plate 29 in a clockwiseor counterclockwise direction could bemade toactuate any other type ofmechanism. Furthermore, instead of mounting the pendulum and dog in thecase and. cover, they may be mounted on any other frame or structure.

For any given spring 26, the depth of the notch 29 determines theacceleration upon which the arm 3 will swing .counterrclockwisesufficiently .to release the dog 22. Thedeeper thenotch, .thexgreatertherequired acceleration for such release. For any given spring-2 6, thelength oftheears li and 25, from-the center ofipivot 23, willdeterminethe magnitude of the accelerationat which-the arm 3 begins. itsclockwise rotation and thereforetheacceleratiodat: which the contacts17open. The

longer ,the ears the smaller this acceleration and. the later.theperiodjntime atwhichthe contacts open.

pt an .t c e smav .b m d hin t bi 9f h invention as set forth in theappended claims.

We claim:

1. A mechanism, responsive to acceleration, comprising a frame, apendulum, a hinge for said pendulum, said hinge being mounted in saidframe, a latch dog hingedly mounted in said frame, a recess in saidpendulum, one end of said dog being positioned in said recess, a springbiasing said pendulum, and means operatively connected to said pendulumfor actuation of said means on deflection of said pendulum uponacceleration of said frame, said means including also means forsubsequently actuating said first-mentioned means upon a differentacceleration of said frame.

2. A mechanism, responsive to acceleration, comprising a frame, apendulum, a hinge for said pendulum, said hinge being mounted in saidframe, a latch dog hingedly mounted in said frame, a recess in saidpendulum, one end of said dog being positioned in said recess, a springbiasing said pendulum, an electrical switch mechanism, and an operativeconnection between said switch mechanism and said pendulum to actuatesaid switch mechanism upon deflection of said pendulum in one direction,said connection actuating said switch mechanism upon deflection of thependulum in an opposite direction.

3. A mechanism, responsive to acceleration, comprising a frame, apendulum, a hinge for said pendulum pendulum,

mounted in said frame, a latch for said pendulum, means responsive toacceleration of said frame in a predetermined direction for unlatchingsaid pendulum, and a spring connected to said frame and said pendulumfor biasing said pendulum against rotation about said hinge, saidpendulum rotating about said hinge upon acceleration of said frame andmeans responsive to this said rotation of said pendulum and actuatedthereby, said means also including means for actuation by said pendulumupon a reverse rotation of said pendulum upon a different accelerationof said frame.

4. A switch mechanism, responsive to acceleration, comprising a frame, apendulum, a hinge for said pendulum mounted in said frame, a latch forsaid pendulum, means responsive to acceleration of said frame in apredetermined direction for unlatching said pendulum, a spring connectedto said frame and said pendulum for biasing said pendulum againstrotation about said hinge, an electrical switch connected to saidpendulum for actuation of said switch on rotation of said pendulum, saidmeans including also means for subsequently actuating saidfirst-mentioned means upon a different acceleration of said frame.

5. A switch, responsive to acceleration, comprising a frame, a pendulummounted on said frame, a bracket mounted on said pendulum, a pair ofelectrical contacts mounted on said frame, a bell crank hingedly mountedon said frame, a notch in said pendulum, one end of said bell crankbeing positioned in said notch, a spring connecting the other end ofsaid bell crank and to said means mounted on said pendulum andoperatively connected to said contacts for actuation of said switch onrotation of said pendulum about its hinge.

6. A switch, responsive to acceleration, comprising a frame, a pendulummounted on said frame, a bracket mounted on said pendulum, a pair ofelectrical spring contacts mounted on said frame at one side of saidpendulum and also to one side of said bracket, a bell crank hingedlymounted in said frame, a notch in said pendulum, one end of said bellcrank being positioned in said notch, a spring connecting the other endof said bell crank and to said pendulum, said bracket contacting one ofsaid spring electrical contacts when the pendulum is in locked positionwith the bell crank end positioned in said notch.

7. A mechanism, responsive to acceleration, comprising a frame, apendulum hingedly mounted on said frame, a latch for said pendulum tohold said pendulum in a fixed position, means responsive to accelerationin one direction to release said pendulum from said latch and to permitsaid pendulum to swing freely on said hinge in one direction uponacceleration of said mechanism,

and means connected to said pendulum for actuation by said pendulum whensaid pendulum swings in an opposite direction at a predetermined lessermagnitude of acceleration of said mechanism.

8. A mechanism, responsive to acceleration, comprising a frame, apendulum hingedly mounted on said frame, a latch for said pendulum tohold said pendulum in a fixed position, means responsive to accelerationin one direction to release said pendulum from said latch and to permitsaid pendulum to swing freely on said hinge upon acceleration of saidmechanism, and means connected to said pendulum for actuation by saidpendulum upon a predetermined magnitude of deceleration of saidmechanism when said pendulum swings in a direction opposite to thedirection of swing of said pendulum on said acceleration of saidmechanism.

9 A mechanism, responsive to acceleration, comprising a frame, apendulum hingedly mounted on said frame, a latch for said pendulum tohold said pendulum in a fixed position, means responsive to accelerationin one direction to release said pendulum from said latch and to permitsaid pendulum to swing freely on said h nge in one direction uponacceleration of said mechanism, and means connected to said pendulum foractuation by said pendulum when said pendulum swings in an oppositedirection at a predetermined deceleration of said mechanism.

10. A mechanism, responsive to acceleration, comprising a frame, a mass,a mount for said mass on said frame, said mass being movably mounted onsaid mount on acceleration of said frame, releasable means mounted insaid frame to restrain said mass from motion on acceleration of saidframe, said releasable means being actuable upon a predeterminedacceleration of said frame to release said mass, said mass moving onsaid mount upon said acceleration of said frame in one direction aftersaid release, said mechanism including means for moving said mass onsaid mount upon a predetermined acceleration of said frame differentfrom said first mentioned acceleration, a motion responsive deviceresponsive to the motion of said mass, said motion responsive deviceincluding means responsive to the motion of said mass upon a lesseracceleration of said frame.

' 11. A mechanism, responsive to acceleration, comprising a frame, amass, a mount for said mass on said frame, said mass being movablymounted on said mount, releasable means mounted in said frame torestrain said mass from motion on acceleration of said frame, saidreleasable means being actuable upon a predetermined acceleration ofsaid frame to release said mass, said mass moving on said mount uponsaid acceleration in one direction after said release, said mechanismincluding means for moving said mass on said mount upon a predetermineddeceleration of said frame, and a motion responsive device responsive tothe motion of said mass, said motion responsive device including meansresponsive to the reverse motion of said mass upon a predetermineddeceleration of said mechanism.

Paul July 19, 1932 Grant et al. June 20, 1944

